There is strong evidence that disability among older adults is largely driven by illnesses and injuries that lead to hospitalizations. Data shows the likelihood of developing new or worsening disability, as well as a reduced likelihood of recovery from disability, is greatly increased with hospitalization. Our work has shown low mobility to be associated with adverse outcomes including decline in activities of daily living (ADLs), nursing home placement and death, even after controlling for illness severity and comorbidity. Intervention studies examining the effect o increasing mobility during hospitalization are sparse and typically measure in-hospital outcomes such as length of stay. However in our VA-funded study, we showed patients who received an in-hospital mobility intervention that included twice daily assistance with walking and a behavioral strategy that addressed barriers to mobility, setting of mobility goals, and encouraged patients to walk, had a clinically significant higher level of community mobility at one month post-discharge compared to usual care. This preliminary work was restricted to only one month of follow-up of veterans who were ? 65 years of age. A number of important gaps remain in our understanding of the impact of a hospital mobility program: 1) hospital mobility program studies have not used a randomized controlled trial (RCT) design to evaluate the impact; 2) the actual number of steps and time spent walking by participants has not been measured; 3) outcomes beyond 30 days post-discharge have not been examined; and 4) characteristics of patients most likely to benefit from this type of intervention has not been identified. For this high impact stud we propose to use a stepped wedge cluster randomization design on five VA hospital wards to compare a mobility program (MP) to usual care (UC) among a cohort of veterans age ? 50 years. We will examine mobility and adverse outcomes including functional decline, nursing home admission, emergency department (ED) visits, hospitalization and death in the MP and UC groups in the year after hospital discharge using in-hospital and post-hospital assessments. Our overarching hypothesis is that a hospital mobility program that provides assistance with ambulation during hospitalization will reduce the observed loss of mobility and adverse outcomes associated with hospitalization and this difference between MP and UC will be maintained throughout the year follow-up period. The major aims of this research project are to test the effectiveness of a mobility program on recovery to pre-hospital mobility status or better and reduction of adverse outcomes including functional decline, ED visits, hospitalization, nursing home admission and death in the year after hospitalization; and to identify characteristics that modify the effect of the mobility intervention on recovery to pre-hospital mobility status or better and reduction of adverse outcomes in the year after hospitalization. A successful mobility intervention that prevents loss of mobility or quickens recovery to pre-hospital levels could significantly impact quality of life and reduce disability for thousands of hospitalized patients. This line of research has the potential to change the standard of hospital care provided to all patients.